New insight into gas sensing performance of nanoneedle-assembled and nanosheet-assembled hierarchical NiO nanoflowers.

Nanoneedle-assembled hierarchical and nanosheet-assembled hierarchical NiO nanoflowers were successfully synthesized via a facile hydrothermal method and subsequent calcination. And we proposed their growth mechanisms and the influences on gas-sensing properties. The results indicated that the gas sensing properties of NiO nanocrystals can be dramatically enhanced by tailoring the nanoscale building blocks. In addition, it was surprisingly noticed that the nanoneedle-assembled hierarchical NiO structures exhibited quicker gas response and recovery than the nanosheet-assembled ones. While nanosheet-assembled hierarchical NiO nanoflowers demonstrated higher gas response towards ethanol. [ABSTRACT FROM AUTHOR]